• 공업화학
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• 제27권4호
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• pp.380-385
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• 2016

최근 셀룰로오스 나노피브릴과 셀룰로오스나노크리스탈과 같은 나노셀룰로오스는 관심의 초점이 되고 있다. 나노셀룰로오스의 표면에 있는 수산기는 고분자복합체의 보강재로 사용함에 있어서 적합한 기능을 소유하고 있기 때문이다. 본 연구에서 나노셀룰로오스를 시멘트복합체 제조에 있어서 보강재로서 사용하였다. 나노셀룰로오스는 TEMPO 산화에 의한 전처리과정을 거친 후, 균질화 및 초음파처리에 의해서 제조되었고, 투과전자현미경으로 나노셀룰로오스를 분석한 결과 직경이 10에서 15 nm 범위로 나타났다. 0.5% 나노셀룰로오스가 함유된 시멘트복합체의 압축강도를 기존 시멘트복합체와 비교하였으며 특히, 인장강도와 휨강도가 기존 시멘트복합체에 비해서 각각 49.7%와 38.8% 개선되었다. 그리고 나노셀룰로오스가 혼합된 시멘트복합체의 자기수축률은 타설 후 1일 경과 시 18.9%, 28일 경과 시 5.9%의 저감효과가 나타났다.

• Bulletin of the Korean Chemical Society
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• 제24권8호
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• pp.1181-1187
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• 2003

Condensation of 4-cyano-5,6-dimethyl-3-pyridazinone 1 with aromatic aldehydes gave the novel styryl derivatives 2a-c. Refluxing of compound 2a with phosphorus oxychloride furnished 3-chloropyridazine derivative 3. Compound 3 was reacted with thiourea and produced pyridazine-3(2H)thione 4. Thieno[2,3-c]- pyridazines 5a-e were achieved by cycloalkylation of compound 4 with halocompounds in methanol under reflux and in the presence of sodium methoxide. Also, refluxing of compound 4 with N-substituted chloroacetamide in the presence of potassium carbonate afforded thienopyridazines 6a-e. Cyclization of compound 6 with some electrophilic reagents as carbon disulfide and triethyl orthoformate furnished the novel pyrimido[4',5':4,5]thieno[2,3-c]pyridazines 12 and 13a-c, respectively. Diazotisation of compound 6 with sodium nitrite in acetic acid produced the pyridazino[4',3':4,5]thieno[3,2-d][1,2,3]triazines 14a-c. Ternary condensation of compound 1, aromatic aldehydes and malononitrile in ethanol containing piperidine under reflux afforded the novel phthalazines 16a-c. Compound 3 was subjected to some nucleophilic substitution reactions with amines and sodium azide and formed the aminopyridazines 17a, b and tetrazolo[1,5-b]-pyridazine 19, respectively. The structures of the synthesized compounds were established by elemental and spectral analyses.

• Bulletin of the Korean Chemical Society
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• 제32권6호
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• pp.1907-1911
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• 2011

A kinetic study is reported for nucleophilic substitution reactions of 4-pyridyl X-substituted benzoates 7a-e with a series of alicyclic secondary amines in H2O. The Br${\o}$nsted-type plot for the reactions of 4-pyridyl benzoate 7c is linear with ${\beta}_{nuc}$ = 0.71. The corresponding reactions of 2-pyridyl benzoate 6, which is less reactive than 7c, resulted in also a linear Br${\o}$nsted-type plot with ${\beta}_{nuc}$ = 0.77. The fact that the more reactive 7c results in a smaller ${\beta}_{nuc}$ value appears to be in accord with the reactivity-selectivity principle. The aminolysis of 7c has been suggested to proceed through a stepwise mechanism in which breakdown of the intermediate is the rate-determining step (RDS). The Hammett plot for the reactions of 7a-e with piperidine consists of two intersecting straight lines, i.e., ${\rho}_X$ = 1.47 for substrates possessing an electron-donating group (EDG) and ${\rho}_X$ = 0.91 for those possessing an electron-withdrawing group (EWG). In contrast, the corresponding Yukawa-Tsuno plot exhibits excellent linear correlation with ${\rho}_X$ = 0.79 and r = 0.56. Thus, it has been concluded that the nonlinear Hammett plot is not due to a change in the RDS but is caused by stabilization of the ground state of the substrates possessing an EDG through resonance interaction between the EDG and the C=O bond of the substrates.

• 한국응용곤충학회지
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• 제51권2호
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• pp.149-152
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• 2012

잎침지법을 이용하여 후추 열매 메탄올 추출물 및 분리된 화합물들의 배추좀나방(Plutellaxylostella) 유충에 대한 살충 활성을 검정하였다. 후추 열매 메탄올 추출물은 배추좀나방 유충에 대해 5.0과 2.5 mg/mL 농도에서 각각 100%와 97%의 살충 활성을 보였다. 후추 열매에서 유래된 화합물들의 배추좀나방에 대한 살충 활성을 조사한 결과, guineensine ($LC_{50}$=0.013 mg/mL)의 살충 활성이 가장 높았으며, 다음으로 retrofractamide A (0.020 mg/mL), pipercide (0.033 mg/mL) 그리고 pellitorine (0.046 mg/mL) 순이었다. Piperine의 반수치사농도는 0.5 mg/mL 이상이었다.

• Asian Pacific Journal of Cancer Prevention
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• 제13권5호
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• pp.1957-1962
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• 2012

Bladder cancer is a common malignancy worldwide. Despite the increased use of cisplatin-based combination therapy, the outcomes for patients with advanced disease remain poor. Recently, altered activation of the PI3K/Akt/mTOR pathway has been associated with reduced patient survival and advanced stage of bladder cancer, making its upstream or downstream components attractive targets for therapeutic intervention. In the present study, we showed that treatment with DTCM-glutaramide, a piperidine that targets PDK1, results in reduced proliferation, diminished cell migration and G1 arrest in 5637 and T24 bladder carcinoma cells. Conversely, no apoptosis, necrosis or autophagy were detected after treatment, suggesting that reduced cell numbers in vitro are a result of diminished proliferation rather than cell death. Furthermore previous exposure to 10 ${\mu}g/ml$ DTCM-glutarimide sensitized both cell lines to ionizing radiation. Although more studies are needed to corroborate our findings, our results indicate that PDK1 may be useful as a therapeutic target to prevent progression and abnormal tissue dissemination of urothelial carcinomas.

• 공업화학
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• 제20권2호
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• pp.172-176
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• 2009

Solder resist ink와 회로표면과의 밀착력 향상을 위해 사용되는 soft etching 제의 기본 조성으로 과산화수소와 황산을 선정하고 inhibitor, 계면활성제, 안정제를 첨가하여 에칭 속도 $0.7{\sim}1{\mu}m/min$, 표면조도(Ra)값 $0.5{\sim}0.6{\mu}m$을 만족시키는 soft etching 제 개발을 위한 연구를 하였다. Inhibitor로는 butyl amine, cyclohexyl amine, 5-aminotetrazole (5-Azol)을 첨가하였으며 계면활성제로는 polyethylene glycol (PEG), polyethylene imine (PEI), piperidine을 안정제로는 butyl alcohol, isopropanol, 인산을 첨가하여 각각의 첨가제가 에칭 속도 및 표면조도에 미치는 영향을 비교 분석하였다. 본 연구 결과 과산화수소 3% 황산 4%에 5-Azol 500 ppm, PEI 600 ppm, 인산 10 ppm 첨가 시 $0.7~1{\mu}m/min$을 만족시키는 에칭속도와 가장 좋은 표면조도를 갖는 것을 확인하였으며 solder test 결과 solder resist ink의 들뜸 현상이 발생하지 않는 것을 확인하였다.

• Bulletin of the Korean Chemical Society
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• 제31권1호
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• pp.75-81
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• 2010

The reaction of N,N-diethyl carbamates of 1H-[1,2,3]triazolo[4,5-b]pyridin-1-ol (4-HOAt) 7, 3H-[1,2,3]triazolo[4,5-b]pyridin-3-ol (7-HOAt) 8, 1H-benzo[d][1,2,3]triazol-1-ol (HOBt) 9, 6-chloro-1H-benzo[d][1,2,3]triazol-1-ol (Cl-HOBt) 10, 6-(trifluoromethyl)-1H-benzo[d][1,2,3]triazol-1-ol ($CF_3$-HOBt) 11, and 6-nitro-1H-benzo[d][1,2,3]triazol-1-ol ($NO_2$-HOBt) 12 with morpholine and piperidine in $CH_3CN$ underwent acyl nucleophilic substitution to give the corresponding carboxamide derivatives. The reactants and products were identified by elemental analysis, IR and NMR. We measured the kinetics of these reactions spectrophotometrically in $CH_3CN$ at a range of temperatures. The rates of morpholinolysis and piperidinolysis were found to fit the Hammett equation and correlated with $\sigma$-Hammett values. The values were 1.44 - 1.21 for morpholinolysis and 1.95 - 1.72 for piperidinolysis depending on the temperature. The $Br{\phi}$nsted-type plot was linear with a $\beta_lg = -0.49 \pm 0.02$ and $-0.67 \pm 0.03$. The kinetic data and structure-reactivity relationships indicate that the reaction of 9-12 with amines proceeds by a concerted mechanism. The deviation from linearity of the correlation ${\Delta}H^#$ vs. ${\Delta}S^#$ and plot of $logk_{pip}$ vs. $logk_{morph}$ and $Br{\phi}$nsted-type correlation indicate that the reactions of amines with carbamates 7 and 8 is attributed to the electronic nature of their leaving groups.

• Bulletin of the Korean Chemical Society
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• 제35권2호
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• pp.471-476
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• 2014

A kinetic study on aminolysis of 2-chloro-4-nitrophenyl X-substituted-benzoates (2a-k) in 80 mol % $H_2O/_20mol%$ DMSO at $25.0^{\circ}C$ is reported. The Br${\emptyset}$nsted-type plot for the reactions of 2-chloro-4-nitrophenyl benzoate (2g) with a series of cyclic secondary amines curves downward (e.g., ${\beta}_1=0.25$, ${\beta}_2=0.85$ and $pK_a^o=10.3$), which is typical of reactions reported to proceed through a stepwise mechanism with a change in ratedetermining step (RDS). The Hammett plot for the reactions of 2a-k with piperidine consists of two intersecting straight lines, while the corresponding Yukawa-Tsuno plot exhibits an excellent linear correlation with ${\rho}_X=1.15$ and r = 0.59. Thus, it has been concluded that the nonlinear Hammett plot is not due to a change in RDS but is caused by stabilization of substrates through resonance interactions between the electron-donating substituent and the C=O bond. Substrates possessing a substituent at the 2-position of the leaving aryloxide deviate negatively from the curved Br${\emptyset}$nsted-type plot for the reactions of Y-substituted-phenyl benzoates (3a-i), implying that the steric hindrance exerted by the substituent at the 2-position is an important factor which governs the reactivity of Y-substituted-phenyl benzoates.

• Bulletin of the Korean Chemical Society
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• 제34권10호
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• pp.2983-2988
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• 2013

Second-order rate constants ($k_N$) have been measured spectrophotometrically for the reactions of 4-chloro-2-nitrophenyl X-substituted-benzoates (1a-1h) with a series of cyclic secondary amines in 80 mol % $H_2O$/20 mol % DMSO at $25.0{\pm}0.1^{\circ}C$. The Hammett plot for the reactions of 1a-1h with piperidine consists of two intersecting straight lines, while the Yukawa-Tsuno plot exhibits an excellent linear correlation with ${\rho}_X $ = 1.25 and r = 0.58, indicating that the nonlinear Hammett plot is not due to a change in the rate-determining step (RDS) but is caused by ground-state stabilization through resonance interactions for substrates possessing an electron-withdrawing group in the benzoyl moiety. The Br${\o}$nsted-type plot for the reactions of 4-chloro-2-nitrophenyl benzoate (1d) with a series of cyclic secondary amines curves downward with ${\beta}_2$ = 0.85, ${\beta}_1$ = 0.24, and $pK_a{^o}$ = 10.5, implying that a change in RDS occurs from the $k_2$ step to the $k_1$ process as the $pK_a$ of the conjugate acid of the amine exceeds 10.5. Dissection of $k_N$ into the microscopic rate constants $k_1$ and $k_2/k_{-1}$ ratio associated with the reaction of 1d reveals that $k_2$ is dependent on the amine basicity, which is contrary to generally held views.

• 한국식품과학회지
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• 제33권2호
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• pp.216-220
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• 2001

이 연구에서는 산화 셀룰로오스가 케이크 등과 같은 식품에서 식이섬유 소재로 사용될 수 있는지 그 가능성을 조사하기 위하여, TEMPO, NaBr 및 NaOCl을 동시에 사용하여 셀룰로오스 내의 1차 알코올기를 산화시키고, 산화 셀룰로오스를 밀가루 함량의 10%수준으로 대체하여 제조한 케이크의 이화학적 및 관능적 특성을 평가하였다. 그 결과 산화 셀룰로오스를 함유한 케이크는 산화 셀룰로오스를 첨가하지 않은 대조군보다 전체적으로 색이 어둡고 노란색이 강하였으나, 전체적인 부피는 증가하는 것으로 나타났다. 관능적 평가 결과 셀룰로오스를 첨가한 케이크는 가루끼 특성이 강하게 나타난 반면, 산화 셀룰로오스를 첨가한 케이크는 대조군과 가루끼 특성에서는 유의적인 차이를 보이지 않았고, 단단한 정도는 적고 촉촉한 정도는 더 크게 나타나, 산화 셀룰로오스를 케이크에 첨가시 텍스처 특성이 오히려 향상되는 것으로 나타났다. 이 실험 결과 산화 셀룰로오스는 케이크에서 외관이나 텍스처 특성의 저하없이 식이섬유 소재로 사용될 수 있음을 알 수 있었다.